arch/m68k-amiga/devs/ata/waitnano.c

   1 /*
   2     Copyright © 2013, The AROS Development Team. All rights reserved
   3     $Id$
   4 */
   5
   6 #include <exec/types.h>
   7 #include <exec/io.h>
   8 #include <hardware/cia.h>
   9 #include <aros/debug.h>
  10
  11 #include "timer.h"
  12 #include "ata.h"
  13
  14 BOOL ata_Calibrate(struct IORequest* tmr, struct ataBase *base)
  15 {
  16     base->ata_ItersPer100ns = 1;
  17     return TRUE;
  18 }
  19
  20 static void busywait(UWORD cnt)
  21 {
  22     asm volatile (
  23         "move.w %0,%%d0\n"
  24         "lea 0xbfe001,%%a0\n"
  25         "0:\n"
  26         "tst.b (%%a0)\n"
  27         "tst.b (%%a0)\n"
  28         "tst.b (%%a0)\n"
  29         "tst.b (%%a0)\n"
  30         "dbf %%d0,0b\n"
  31     : : "m" (cnt) : "d0", "a0");
  32 }
  33
  34 /* Single CIA access = 1 E-clock */
  35 void ata_WaitNano(ULONG ns, struct ataBase *base)
  36 {
  37     ns /= 2;
  38     if (!(SysBase->AttnFlags & AFF_68020))
  39         ns /= 2;
  40     while (ns >= 65536 * 4) {
  41         busywait(65535);
  42         ns -= 65536 * 4;
  43     }
  44     if (ns >= 4)
  45         busywait(ns / 4);
  46 }